1. Field of the Invention
The invention relates to automated systems for permitting authorized persons to access secured buildings or other areas while preventing such access by unauthorized persons. More particularly, the invention relates to an access control system which identifies authorized persons and permits access by the authorized person and their approved guests while permitting monitoring and recording of access.
2. Description of the Related Art
The invention relates to controlling access into a restricted area and thus the term xe2x80x9caccessxe2x80x9d, as used herein, refers to physical entry into a building, or other restricted area, such as a room, a locker, a cabinet, or the like. However, the restricted area can be the exterior of a building or the like and thus the invention can be applied to controlling entry into or exit out of a building or other area. There have always been situations in which it was desirable to restrict access to certain physical areas to a select person or group of people. Such restricted access has been accomplished by fences, walls, locks and other barriers. However, even the use of barriers has not prevented unauthorized access. Accordingly, it has been necessary in many instances to provide human surveillance in the form of a security guard or receptionist at an entrance to an area or through the use of video cameras or the like to transmit images to persons at a remote or centralized location. Of course, the use of personnel and video cameras can become expensive and is only as reliable as the personnel and their state of alertness at any particular time.
The complexities of modern society have only served to increase the need for access control. For example, many government agencies and contractors work on matters that are of a confidential or even xe2x80x9ctop secretxe2x80x9d nature. In fact, most workplaces, such as offices, warehouses, and even retail stores in some instances, have a need to implement access control to prevent the theft of intellectual property and/or goods. Further, xe2x80x9cmembers onlyxe2x80x9d establishments, such as health clubs, country clubs, and the like, may derive revenue from membership fees and thus must restrict access to current members and approved guests. Of course, the use of personnel to monitor access adds significant financial overhead. However, particularly in members only establishments, the costs of monitoring personnel must be balanced with the loss of revenue due to access by non members or non approved guests. Therefore, many members only establishments have an employee stationed at the entrance during all hours of operation. The salary, benefits, and other costs associated with such an extra employees are significant.
Many members only establishments issue identification cards to their members, employees and other authorized personnel. Often, the identification card includes a picture of the authorized person. However, such an identification card s till requires a security guard or other personnel for verification. Also, such cards are easily forged by replacing the picture with that of an unauthorized person. To overcome these limitations, it is known to provide the authorized person with a personal identification number (PIN) or other identifying code. The identifying code can be encoded in a magnetic strip or the like in a security card and read by an automated reader at an entrance to grant access only to persons having the card. Alternatively, the code can be entered by the user on a keypad to gain access. However, the use of identifying-codes also drawbacks in access control applications. In particular, the identification card can be stolen or the user can be forced under duress to reveal their code. In such cases, unauthorized possessors of the card or code can gain access to a restricted area.
The use of biometrics has been proposed as a solution to the limitations noted above. Generally, the term xe2x80x9cbiometricsxe2x80x9d refers to the study of measurable biological characteristics, i.e. biometric parameters, of a living being. In the context of security, xe2x80x9cbiometricsxe2x80x9d refers to techniques that rely on a unique, measurable characteristic of a living being for automatically recognizing or verifying identity. Examples of biometric parameters are facial data, retinal data, fingerprint data, speech data, and the like.
Generally, biometric systems operate in the following manner. First, a system captures a sample of at least one biometric parameter of an authorized person during an xe2x80x9cenrollmentxe2x80x9d process. The parameters are then converted by the system into a mathematical code, i.e., data, that is stored as the biometric template representing measured biometric parameters for that person. Central to a biometric system is the xe2x80x9cenginexe2x80x9d which processes the biometric data in accordance with various algorithms or other processing mechanisms.
Some biometric systems use xe2x80x9cidentificationxe2x80x9d methods and some use xe2x80x9cverificationxe2x80x9d methods. In identification systems, a sample is presented to the biometric system and the system then attempts to find out who the sample belongs to by comparing the sample with a plurality of templates obtained through enrollment. Verification systems on the other hand perform a one-to-one process where the biometric system is seeking to verify identity. A single biometric sample is matched against a single template obtained during enrollment. If the two match, the system effectively confirms that the person actually is who he presents himself to be. The key difference between these two approaches centers on the logic addressed by the biometric system and how these fit within a given application. Identification systems decide who the person is and can check whether more than one matching biometric template exists. Accordingly, identification systems can deny access to an individual who is attempting to pass himself off with more than one identity. Verification, on the other hand only decides if the person is who he says he is. Accordingly, identification systems are more versatile and powerful. However, verification systems generally require less processing horsepower and thus are commonly used.
In typical biometric access control systems, biometric sensors are placed proximate entrances and are linked to a central computer having the engine and biometric xe2x80x9cenrollmentxe2x80x9d data, i.e., templates, representing biometric parameters of authorized users collected from a central enrollment station. If the biometric parameter collected at the entrance matches a template stored in the central computer, access is granted. However, conventional biometric systems have several limitations. In particular, the sensing accuracy of certain biometric parameters, such as facial parameters, retinal parameters, and the like can be highly dependent on the environment in which the parameters are sensed. For example, the lighting intensity, angle and color will affect sensing of biometric parameters. Accordingly, the ability to reliably match data representing parameters collected at an entrance with data of templates collected during enrollment is limited, especially when the entrance is an external entrance where the weather, season, and time of day will affect lighting significantly. Also, sensing biometric parameters, converting the parameters to data, communicating the data to a central computer, and comparing the data parameters with templates of enrollment data in the central computer is relatively time consuming, even with high speed computers and communication links. Accordingly, such systems present significant inconveniences to the authorized persons through improperly rejected access and time delays prior to granting access. Further, the use of a centralized computer for storing enrollment data also renders each entrance dependent on the central computer.
The use of less environmentally affected biometric parameters, such as fingerprint parameters can alleviate some of the problems noted above. However, sensing such parameters requires that the person desiring access make physical contact with a sensor, such as a fingerprint scanner, upon each entry request. Also, such parameters are easily affected by skin debris, and skin blemishes. Therefore, the person desiring access may have to wipe off their finger, not to mention remove any gloves, prior to submitting to the physical contact with the sensor. The match tolerance between a template and data corresponding to a measured parameter can be increased to minimize lockout of authorized users. However, such an approach inherently reduces the accuracy and effectiveness of the system by increasing the likelihood of allowing access to unauthorized users.
Further, known automated access control systems including biometric systems, do not address the specific needs of members only institutions, such as the need to prevent unauthorized persons from entering on the xe2x80x9ccoattailsxe2x80x9d of an authorized person, a technique referred to as xe2x80x9ctailgatingxe2x80x9d herein. Also, known automated access control systems do not permit non-member, approved guests of members, to enter in an authorized manner. Also, such systems do not provide adequate records of member and guest entry and do not provide flexible control and reporting of such entry.
U.S. Pat. No. 5,305,390 discloses a system for recognizing and counting people as they move past a particular point. This patent also discloses a security system application in which the system is used to detect if an unauthorized person follows an authorized person into the secured area (see column 4, lines 47-66). This reference does not relate to biometric security devices and does not provide access for guests. Accordingly, the system disclosed in U.S. Pat. No. 5,305,390 is not suitable for typical members only institutions.
U.S. Pat. No. 5,283,644 discloses a monitoring system in which presence is detected in a protected area. Upon detecting a presence, image data is collected by a camera and collated with image data of authorized persons. If the image data does not match image data of authorized persons, the presence is reported to security through report data. This reference relates to internal surveillance and not access control.
U.S. Pat. No. 5,280,266 discloses a visitor sensing device capable of being combined with a conventional intercom. When a visitor is present at a door for a specified period of time, a live image of the visitor is displayed to the occupant and an audible alarm is sounded. This reference does not relate to biometric recognition and requires that a receptionist or security person be present to review the image and converse over the intercom. Accordingly, the device disclosed in U.S. Pat. No. 5,280,266 does not eliminate the overhead associated with access personnel.
It is an object of the invention to overcome the limitations of the known systems described above.
It is another object of the invention to, obviate or limit the need for access control personnel.
It is another object of the invention to automatically control access to a members only establishment;
It is another object of the invention to permit access to guests of members of a members only establishment when appropriate;
It is another object of the invention to record data relating to guest access.
It is another object of the invention to minimize the inconvenience an obtrusiveness of biometric identification access control.
It is another object of the invention to minimize the effect of environmental variables in biometric identification access control.
It is another object of the invention to automatically indicate any security anomaly in an access control system.
A first aspect of the invention is an access control apparatus for selectively granting access to an area comprising a controller including a processor and memory, a data collection device coupled to the controller, a access control device, a video camera, and a sensor configured to monitor an entrance to the area. The controller is operative to compare entrance data, which includes identification data, collected by the data collection device with stored data in the memory and to operate the access control device to grant access to the area when the identification data corresponds to the stored data. The controller also is operative to repeatedly record image data output by the video camera in the memory for a predetermined period of time and to present the image data for review when a signal from the sensor indicate that a number of people entering the area does not correspond to the number of people indicated by the entrance data.
A second aspect of the invention is a method of controlling access to an area comprising the steps of, comparing entrance data, which includes identification data, collected by a data collection device proximate an entrance to the area with stored data, granting access to the area when the identification data corresponds to the store data, counting persons accessing the area, repeatedly recording image data for a predetermined period of time and presenting the image data for review when a number of people counted during the counting step does not correspond to the number of people indicated by the entrance data.